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1.
Nat Commun ; 11(1): 3839, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32737294

RESUMO

Chromatin regulates spatiotemporal gene expression during neurodevelopment, but it also mediates DNA damage repair essential to proliferating neural progenitor cells (NPCs). Here, we uncover molecularly dissociable roles for nucleosome remodeler Ino80 in chromatin-mediated transcriptional regulation and genome maintenance in corticogenesis. We find that conditional Ino80 deletion from cortical NPCs impairs DNA double-strand break (DSB) repair, triggering p53-dependent apoptosis and microcephaly. Using an in vivo DSB repair pathway assay, we find that Ino80 is selectively required for homologous recombination (HR) DNA repair, which is mechanistically distinct from Ino80 function in YY1-associated transcription. Unexpectedly, sensitivity to loss of Ino80-mediated HR is dependent on NPC division mode: Ino80 deletion leads to unrepaired DNA breaks and apoptosis in symmetric NPC-NPC divisions, but not in asymmetric neurogenic divisions. This division mode dependence is phenocopied following conditional deletion of HR gene Brca2. Thus, distinct modes of NPC division have divergent requirements for Ino80-dependent HR DNA repair.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/genética , Proteína BRCA2/genética , Cromatina/química , Proteínas de Ligação a DNA/genética , Células-Tronco Neurais/metabolismo , Neurogênese/genética , Reparo de DNA por Recombinação , ATPases Associadas a Diversas Atividades Celulares/deficiência , Animais , Apoptose/genética , Proteína BRCA2/deficiência , Divisão Celular , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina , DNA/genética , DNA/metabolismo , Quebras de DNA de Cadeia Dupla , Proteínas de Ligação a DNA/deficiência , Embrião de Mamíferos , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Camundongos Transgênicos , Neocórtex/citologia , Neocórtex/crescimento & desenvolvimento , Neocórtex/metabolismo , Células-Tronco Neurais/citologia , Transdução de Sinais , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Fator de Transcrição YY1/genética , Fator de Transcrição YY1/metabolismo
2.
PLoS Biol ; 18(8): e3000807, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32760056

RESUMO

Radiotherapy is a commonly used conditioning regimen for bone marrow transplantation (BMT). Cytotoxicity limits the use of this life-saving therapy, but the underlying mechanisms remain poorly defined. Here, we use the syngeneic mouse BMT model to test the hypothesis that lethal radiation damages tissues, thereby unleashing signals that indiscriminately activate the inflammasome pathways in host and transplanted cells. We find that a clinically relevant high dose of radiation causes severe damage to bones and the spleen through mechanisms involving the NLRP3 and AIM2 inflammasomes but not the NLRC4 inflammasome. Downstream, we demonstrate that gasdermin D (GSDMD), the common effector of the inflammasomes, is also activated by radiation. Remarkably, protection against the injury induced by deadly ionizing radiation occurs only when NLRP3, AIM2, or GSDMD is lost simultaneously in both the donor and host cell compartments. Thus, this study reveals a continuum of the actions of lethal radiation relayed by the inflammasome-GSDMD axis, initially affecting recipient cells and ultimately harming transplanted cells as they grow in the severely injured and toxic environment. This study also suggests that therapeutic targeting of inflammasome-GSDMD signaling has the potential to prevent the collateral effects of intense radiation regimens.


Assuntos
Células da Medula Óssea/efeitos da radiação , Transplante de Medula Óssea , Proteínas de Ligação a DNA/genética , Inflamassomos/efeitos da radiação , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteínas de Ligação a Fosfato/genética , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Proteínas de Ligação a DNA/deficiência , Feminino , Fêmur/citologia , Fêmur/metabolismo , Regulação da Expressão Gênica , Inflamassomos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/deficiência , Proteínas de Ligação a Fosfato/deficiência , Piroptose/genética , Piroptose/efeitos da radiação , Transdução de Sinais , Baço/metabolismo , Baço/patologia , Baço/efeitos da radiação , Transplante Isogênico , Irradiação Corporal Total , Raios X
3.
PLoS Genet ; 16(8): e1008953, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32776944

RESUMO

Apoptosis of cochlear hair cells is a key step towards age-related hearing loss. Although numerous genes have been implicated in the genetic causes of late-onset, progressive hearing loss, few show direct links to the proapoptotic process. By genome-wide linkage analysis and whole exome sequencing, we identified a heterozygous p.L183V variant in THOC1 as the probable cause of the late-onset, progressive, non-syndromic hearing loss in a large family with autosomal dominant inheritance. Thoc1, a member of the conserved multisubunit THO/TREX ribonucleoprotein complex, is highly expressed in mouse and zebrafish hair cells. The thoc1 knockout (thoc1 mutant) zebrafish generated by gRNA-Cas9 system lacks the C-startle response, indicative of the hearing dysfunction. Both Thoc1 mutant and knockdown zebrafish have greatly reduced hair cell numbers, while the latter can be rescued by embryonic microinjection of human wild-type THOC1 mRNA but to significantly lesser degree by the c.547C>G mutant mRNA. The Thoc1 deficiency resulted in marked apoptosis in zebrafish hair cells. Consistently, transcriptome sequencing of the mutants showed significantly increased gene expression in the p53-associated signaling pathway. Depletion of p53 or applying the p53 inhibitor Pifithrin-α significantly rescued the hair cell loss in the Thoc1 knockdown zebrafish. Our results suggested that THOC1 deficiency lead to late-onset, progressive hearing loss through p53-mediated hair cell apoptosis. This is to our knowledge the first human disease associated with THOC1 mutations and may shed light on the molecular mechanism underlying the age-related hearing loss.


Assuntos
Proteínas de Ligação a DNA/genética , Surdez/genética , Células Ciliadas Auditivas Internas/metabolismo , Proteínas de Ligação a RNA/genética , Proteína Supressora de Tumor p53/genética , Animais , Apoptose/genética , Benzotiazóis/farmacologia , Proteína 9 Associada à CRISPR/genética , Proteínas de Ligação a DNA/deficiência , Surdez/patologia , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Inativação de Genes , Células Ciliadas Auditivas/metabolismo , Células Ciliadas Auditivas/patologia , Células Ciliadas Auditivas Internas/patologia , Humanos , Camundongos , Mutação , RNA Guia/genética , Transdução de Sinais/efeitos dos fármacos , Tolueno/análogos & derivados , Tolueno/farmacologia , Proteína Supressora de Tumor p53/antagonistas & inibidores , Sequenciamento Completo do Exoma , Peixe-Zebra/genética
4.
Anticancer Res ; 40(8): 4379-4385, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32727766

RESUMO

BACKGROUND/AIM: Identifying patients with DNA mismatch repair-deficient (dMMR) colorectal cancer (CRC) is vital to improve treatment and identify patients with Lynch syndrome (LS). We developed a prediction model for dMMR CRC using clinicopathologic features. PATIENTS AND METHODS: We reviewed the medical records of 1,147 patients who underwent resection of stage I-IV CRC in whom universal screening for LS using immunohistochemistry for MMR proteins had performed. Univariate and multivariate logistic regression analyses were used to build a prediction model of dMMR CRC. RESULTS: The prevalence of dMMR CRC was 5.2%. Age (≥75 years), tumor location (right-sided colon), main histologic features (poor differentiation), maximum tumor size (≥65 mm), and stage (I/II) were independent significant variables related to dMMR. We created a formula for predicting the likelihood of dMMR, and the probability ranged from 0.2% to 83%. CONCLUSION: dMMR CRC can be identified efficiently using clinicopathologic features obtained in daily clinical practice.


Assuntos
Neoplasias Colorretais/patologia , Neoplasias Colorretais/cirurgia , Enzimas Reparadoras do DNA/deficiência , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/metabolismo , Proteínas de Ligação a DNA/deficiência , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Endonuclease PMS2 de Reparo de Erro de Pareamento/deficiência , Modelos Genéticos , Proteína 1 Homóloga a MutL/deficiência , Proteína 2 Homóloga a MutS/deficiência , Estadiamento de Neoplasias , Prevalência , Fatores de Risco
5.
Gene ; 753: 144807, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32461017

RESUMO

Mitochondrial transcription factor A (TFAM), which is required for mitochondrial DNA (mtDNA) transcription, has been linked to metabolic changes that contribute to tumorigenesis and chemoresistance. In this work, we investigated the expression pattern and role of TFAM in hepatocellular carcinoma (HCC). TFAM expression level is similar in 18 out of 20 paired normal liver and HCC tissues with only 2 HCC tissues showing 1.8-fold increase in TFAM. Similar phenomenon was observed in HCC cell lines compared to normal liver lines. Interestingly, TFAM expression is upregulated in resistant HCC cells regardless of the differential TFAM expression level in their parental lines and mechanism of resistance. TFAM depletion led to inhibition of growth and survival but not migration, and sensitization to doxorubicin and sorafenib treatment, through AMPK activation, reduction of nucleoside triphosphates and mitochondrial respiration in HCC cells. In addition, we demonstrated that resistant HCC cell lines were more sensitive to TFAM inhibition than parental lines, and this might be due to the increased mitochondrial biogenesis in resistant HCC cell lines. Our work reveals the preferential role of TFAM in HCC cell response to standard of care drugs, which suggests a potential sensitizing therapeutic target for HCC treatment.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Carcinoma Hepatocelular/tratamento farmacológico , Proteínas de Ligação a DNA/deficiência , Doxorrubicina/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Mitocôndrias/metabolismo , Proteínas Mitocondriais/deficiência , Sorafenibe/farmacologia , Fatores de Transcrição/deficiência , Proteínas Quinases Ativadas por AMP/genética , Adulto , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Transformação Celular Neoplásica , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Mitocôndrias/genética , Proteínas Mitocondriais/antagonistas & inibidores , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação para Cima
6.
Nat Commun ; 11(1): 2598, 2020 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-32451402

RESUMO

DNA double-strand breaks (DSBs) are toxic to mammalian cells. However, during meiosis, more than 200 DSBs are generated deliberately, to ensure reciprocal recombination and orderly segregation of homologous chromosomes. If left unrepaired, meiotic DSBs can cause aneuploidy in gametes and compromise viability in offspring. Oocytes in which DSBs persist are therefore eliminated by the DNA-damage checkpoint. Here we show that the DNA-damage checkpoint eliminates oocytes via the pro-apoptotic BCL-2 pathway members Puma, Noxa and Bax. Deletion of these factors prevents oocyte elimination in recombination-repair mutants, even when the abundance of unresolved DSBs is high. Remarkably, surviving oocytes can extrude a polar body and be fertilised, despite chaotic chromosome segregation at the first meiotic division. Our findings raise the possibility that allelic variants of the BCL-2 pathway could influence the risk of embryonic aneuploidy.


Assuntos
Mutação , Oócitos/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Reparo de DNA por Recombinação/genética , Aneuploidia , Animais , Apoptose , Proteínas Reguladoras de Apoptose/deficiência , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas de Ciclo Celular/deficiência , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Segregação de Cromossomos , Quebras de DNA de Cadeia Dupla , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Endodesoxirribonucleases/deficiência , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/metabolismo , Feminino , Fertilização , Genes bcl-2 , Meiose/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oócitos/citologia , Proteínas de Ligação a Fosfato/deficiência , Proteínas de Ligação a Fosfato/genética , Proteínas de Ligação a Fosfato/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/deficiência , Proteínas Proto-Oncogênicas c-bcl-2/genética , Transdução de Sinais , Proteínas Supressoras de Tumor/deficiência , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Proteína X Associada a bcl-2/deficiência , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
7.
Science ; 368(6497): 1371-1376, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32439659

RESUMO

The effect of immunometabolism on age-associated diseases remains uncertain. In this work, we show that T cells with dysfunctional mitochondria owing to mitochondrial transcription factor A (TFAM) deficiency act as accelerators of senescence. In mice, these cells instigate multiple aging-related features, including metabolic, cognitive, physical, and cardiovascular alterations, which together result in premature death. T cell metabolic failure induces the accumulation of circulating cytokines, which resembles the chronic inflammation that is characteristic of aging ("inflammaging"). This cytokine storm itself acts as a systemic inducer of senescence. Blocking tumor necrosis factor-α signaling or preventing senescence with nicotinamide adenine dinucleotide precursors partially rescues premature aging in mice with Tfam-deficient T cells. Thus, T cells can regulate organismal fitness and life span, which highlights the importance of tight immunometabolic control in both aging and the onset of age-associated diseases.


Assuntos
Senilidade Prematura/imunologia , Proteínas de Ligação a DNA/deficiência , Mitocôndrias/metabolismo , Proteínas Mitocondriais/deficiência , Multimorbidade , Linfócitos T/metabolismo , Fatores de Transcrição/deficiência , Senilidade Prematura/genética , Senilidade Prematura/prevenção & controle , Animais , Síndrome da Liberação de Citocina/imunologia , Proteínas de Ligação a DNA/genética , Feminino , Deleção de Genes , Inflamação/genética , Inflamação/imunologia , Longevidade , Masculino , Camundongos , Camundongos Mutantes , Proteínas Mitocondriais/genética , NAD/administração & dosagem , NAD/farmacologia , Aptidão Física , Linfócitos T/ultraestrutura , Fatores de Transcrição/genética , Fator de Necrose Tumoral alfa/antagonistas & inibidores
8.
Nat Commun ; 11(1): 2135, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32358509

RESUMO

A non-immunogenic tumor microenvironment (TME) is a significant barrier to immune checkpoint blockade (ICB) response. The impact of Polybromo-1 (PBRM1) on TME and response to ICB in renal cell carcinoma (RCC) remains to be resolved. Here we show that PBRM1/Pbrm1 deficiency reduces the binding of brahma-related gene 1 (BRG1) to the IFNγ receptor 2 (Ifngr2) promoter, decreasing STAT1 phosphorylation and the subsequent expression of IFNγ target genes. An analysis of 3 independent patient cohorts and of murine pre-clinical models reveals that PBRM1 loss is associated with a less immunogenic TME and upregulated angiogenesis. Pbrm1 deficient Renca subcutaneous tumors in mice are more resistance to ICB, and a retrospective analysis of the IMmotion150 RCC study also suggests that PBRM1 mutation reduces benefit from ICB. Our study sheds light on the influence of PBRM1 mutations on IFNγ-STAT1 signaling and TME, and can inform additional preclinical and clinical studies in RCC.


Assuntos
Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/metabolismo , Proteínas de Ligação a DNA/metabolismo , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/microbiologia , Fatores de Transcrição/metabolismo , Animais , Complexo Antígeno-Anticorpo/genética , Complexo Antígeno-Anticorpo/metabolismo , Carcinoma de Células Renais/genética , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Feminino , Imunofluorescência , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Imuno-Histoquímica , Neoplasias Renais/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Mutação , Fosforilação , Fator de Transcrição STAT1/metabolismo , Análise Serial de Tecidos , Fatores de Transcrição/deficiência , Fatores de Transcrição/genética , Transcriptoma/genética
9.
PLoS Genet ; 16(4): e1008555, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32271760

RESUMO

Loss of the XPF-ERCC1 endonuclease causes a dramatic phenotype that results in progeroid features associated with liver, kidney and bone marrow dysfunction. As this nuclease is involved in multiple DNA repair transactions, it is plausible that this severe phenotype results from the simultaneous inactivation of both branches of nucleotide excision repair (GG- and TC-NER) and Fanconi anaemia (FA) inter-strand crosslink (ICL) repair. Here we use genetics in human cells and mice to investigate the interaction between the canonical NER and ICL repair pathways and, subsequently, how their joint inactivation phenotypically overlaps with XPF-ERCC1 deficiency. We find that cells lacking TC-NER are sensitive to crosslinking agents and that there is a genetic interaction between NER and FA in the repair of certain endogenous crosslinking agents. However, joint inactivation of GG-NER, TC-NER and FA crosslink repair cannot account for the hypersensitivity of XPF-deficient cells to classical crosslinking agents nor is it sufficient to explain the extreme phenotype of Ercc1-/- mice. These analyses indicate that XPF-ERCC1 has important functions outside of its central role in NER and FA crosslink repair which are required to prevent endogenous DNA damage. Failure to resolve such damage leads to loss of tissue homeostasis in mice and humans.


Assuntos
Reparo do DNA , Proteínas de Ligação a DNA/metabolismo , Endonucleases/metabolismo , Homeostase , Animais , Sangue , Reagentes para Ligações Cruzadas/farmacologia , Dano ao DNA , Reparo do DNA/genética , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Endonucleases/deficiência , Endonucleases/genética , Feminino , Formaldeído/farmacologia , Humanos , Rim/enzimologia , Fígado/enzimologia , Masculino , Camundongos
10.
Am J Hum Genet ; 106(5): 632-645, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32330418

RESUMO

We conducted genome sequencing to search for rare variation contributing to early-onset Alzheimer's disease (EOAD) and frontotemporal dementia (FTD). Discovery analysis was conducted on 435 cases and 671 controls of European ancestry. Burden testing for rare variation associated with disease was conducted using filters based on variant rarity (less than one in 10,000 or private), computational prediction of deleteriousness (CADD) (10 or 15 thresholds), and molecular function (protein loss-of-function [LoF] only, coding alteration only, or coding plus non-coding variants in experimentally predicted regulatory regions). Replication analysis was conducted on 16,434 independent cases and 15,587 independent controls. Rare variants in TET2 were enriched in the discovery combined EOAD and FTD cohort (p = 4.6 × 10-8, genome-wide corrected p = 0.0026). Most of these variants were canonical LoF or non-coding in predicted regulatory regions. This enrichment replicated across several cohorts of Alzheimer's disease (AD) and FTD (replication only p = 0.0029). The combined analysis odds ratio was 2.3 (95% confidence interval [CI] 1.6-3.4) for AD and FTD. The odds ratio for qualifying non-coding variants considered independently from coding variants was 3.7 (95% CI 1.7-9.4). For LoF variants, the combined odds ratio (for AD, FTD, and amyotrophic lateral sclerosis, which shares clinicopathological overlap with FTD) was 3.1 (95% CI 1.9-5.2). TET2 catalyzes DNA demethylation. Given well-defined changes in DNA methylation that occur during aging, rare variation in TET2 may confer risk for neurodegeneration by altering the homeostasis of key aging-related processes. Additionally, our study emphasizes the relevance of non-coding variation in genetic studies of complex disease.


Assuntos
Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Mutação com Perda de Função/genética , Doenças Neurodegenerativas/genética , Proteínas Proto-Oncogênicas/deficiência , Proteínas Proto-Oncogênicas/genética , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Animais , Cognição , Feminino , Demência Frontotemporal/genética , Humanos , Masculino , Camundongos
11.
Clin Sci (Lond) ; 134(7): 727-746, 2020 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-32202295

RESUMO

We previously identified genomic instability as a causative factor for vascular aging. In the present study, we determined which vascular aging outcomes are due to local endothelial DNA damage, which was accomplished by genetic removal of ERCC1 (excision repair cross-complementation group 1) DNA repair in mice (EC-knockout (EC-KO) mice). EC-KO showed a progressive decrease in microvascular dilation of the skin, increased microvascular leakage in the kidney, decreased lung perfusion, and increased aortic stiffness compared with wild-type (WT). EC-KO showed expression of DNA damage and potential senescence marker p21 exclusively in the endothelium, as demonstrated in aorta. Also the kidney showed p21-positive cells. Vasodilator responses measured in organ baths were decreased in aorta, iliac and coronary artery EC-KO compared with WT, of which coronary artery was the earliest to be affected. Nitric oxide-mediated endothelium-dependent vasodilation was abolished in aorta and coronary artery, whereas endothelium-derived hyperpolarization and responses to exogenous nitric oxide (NO) were intact. EC-KO showed increased superoxide production compared with WT, as measured in lung tissue, rich in endothelial cells (ECs). Arterial systolic blood pressure (BP) was increased at 3 months, but normal at 5 months, at which age cardiac output (CO) was decreased. Since no further signs of cardiac dysfunction were detected, this decrease might be an adaptation to prevent an increase in BP. In summary, a selective DNA repair defect in the endothelium produces features of age-related endothelial dysfunction, largely attributed to loss of endothelium-derived NO. Increased superoxide generation might contribute to the observed changes affecting end organ perfusion, as demonstrated in kidney and lung.


Assuntos
Envelhecimento/genética , Senescência Celular/genética , Dano ao DNA , Reparo do DNA , Proteínas de Ligação a DNA/deficiência , Endonucleases/deficiência , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Fatores Etários , Envelhecimento/metabolismo , Envelhecimento/patologia , Animais , Permeabilidade Capilar , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Proteínas de Ligação a DNA/genética , Endonucleases/genética , Células Endoteliais/patologia , Endotélio Vascular/patologia , Endotélio Vascular/fisiopatologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Superóxidos/metabolismo , Rigidez Vascular , Vasodilatação
12.
Am J Surg Pathol ; 44(7): 991-1001, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32205483

RESUMO

Despite their association with DNA mismatch repair (MMR) protein deficiency, colonic adenocarcinomas with mucinous, signet ring cell, or medullary differentiation have not been associated with improved survival compared with conventional adenocarcinomas in most studies. Recent studies indicate that increased T-cell infiltration in the tumor microenvironment has a favorable prognostic effect in colonic adenocarcinoma. However, the prognostic effect of tumor-associated T cells has not been evaluated in histologic subtypes of colonic adenocarcinoma. We evaluated CD8-positive T-cell density in 259 patients with colonic adenocarcinoma, including 113 patients with tumors demonstrating mucinous, signet ring cell, or medullary differentiation, using a validated automated quantitative digital image analysis platform and correlated CD8-positive T-cell density with histopathologic variables, MMR status, molecular alterations, and survival. CD8-positive T-cell densities were significantly higher for MMR protein-deficient tumors (P<0.001), BRAF V600E mutant tumors (P=0.004), and tumors with medullary differentiation (P<0.001) but did not correlate with mucinous or signet ring cell histology (P>0.05 for both). In the multivariable model of factors predicting disease-free survival, increased CD8-positive T-cell density was associated with improved survival both in the entire cohort (hazard ratio=0.34, 95% confidence interval, 0.15-0.75, P=0.008) and in an analysis of patients with tumors with mucinous, signet ring cell, or medullary differentiation (hazard ratio=0.06, 95% confidence interval, 0.01-0.54, P=0.01). The prognostic effect of CD8-positive T-cell density was independent of tumor stage, MMR status, KRAS mutation, and BRAF mutation. Venous invasion was the only other variable independently associated with survival in both the entire cohort and in patients with tumors with mucinous, signet ring cell, or medullary differentiation. In summary, our results indicate that the prognostic value of MMR protein deficiency is most likely attributed to increased tumor-associated CD8-positive T cells and that automated quantitative CD8 T-cell analysis is a better biomarker of patient survival, particularly in patients with tumors demonstrating mucinous, signet ring cell, or medullary differentiation.


Assuntos
Adenocarcinoma/diagnóstico , Biomarcadores Tumorais/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Neoplasias do Colo/diagnóstico , Reparo de Erro de Pareamento de DNA , Proteínas de Ligação a DNA/deficiência , Adenocarcinoma/metabolismo , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Adulto , Idoso , Biomarcadores Tumorais/deficiência , Neoplasias do Colo/metabolismo , Neoplasias do Colo/mortalidade , Neoplasias do Colo/patologia , Feminino , Seguimentos , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida
13.
Mol Immunol ; 120: 93-100, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32113132

RESUMO

Spontaneous DNA-PKcs deficiencies in animals result in a severe combined immunodeficiency (SCID) phenotype because DNA-PKcs is required to activate Artemis for V(D)J recombination coding end hairpin opening. The impact on signal joint formation in these spontaneous mutant mammals is variable. Genetically engineered DNA-PKcs null mice and cells from them show a >1,000-fold reduction in coding joint formation and minimal reduction in signal joint formation during V(D)J recombination. Does chemical inhibition of DNA-PKcs mimic this phenotype? M3814 (also known as Nedisertib) is a potent DNA-PKcs inhibitor. We find here that M3814 causes a quantitative reduction in coding joint formation relative to signal joint formation. The sequences of signal and coding junctions were within normal limits, though rare coding joints showed novel features. The signal junctions generally did not show evidence of resection into the signal ends that is often seen in cells that have genetic defects in DNA-PKcs. Comparison of the chemical inhibition findings here with the known results for spontaneous and engineered DNA-PKcs mutant mammals is informative for considering pharmacologic small molecule inhibition of DNA-PKcs in various types of neoplasia.


Assuntos
Proteína Quinase Ativada por DNA/antagonistas & inibidores , Proteína Quinase Ativada por DNA/genética , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Recombinação V(D)J , Animais , Reparo do DNA , Proteína Quinase Ativada por DNA/deficiência , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/metabolismo , Endonucleases/deficiência , Endonucleases/genética , Endonucleases/metabolismo , Humanos , Técnicas In Vitro , Camundongos , Camundongos Knockout , Camundongos SCID , Mutação , Proteínas Nucleares/deficiência , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Recombinação V(D)J/efeitos dos fármacos
14.
Nat Commun ; 11(1): 1270, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32152280

RESUMO

Prolonged cell survival occurs through the expression of specific protein isoforms generated by alternate splicing of mRNA precursors in cancer cells. How alternate splicing regulates tumor development and resistance to targeted therapies in cancer remain poorly understood. Here we show that RNF113A, whose loss-of-function causes the X-linked trichothiodystrophy, is overexpressed in lung cancer and protects from Cisplatin-dependent cell death. RNF113A is a RNA-binding protein which regulates the splicing of multiple candidates involved in cell survival. RNF113A deficiency triggers cell death upon DNA damage through multiple mechanisms, including apoptosis via the destabilization of the prosurvival protein MCL-1, ferroptosis due to enhanced SAT1 expression, and increased production of ROS due to altered Noxa1 expression. RNF113A deficiency circumvents the resistance to Cisplatin and to BCL-2 inhibitors through the destabilization of MCL-1, which thus defines spliceosome inhibitors as a therapeutic approach to treat tumors showing acquired resistance to specific drugs due to MCL-1 stabilization.


Assuntos
Proteínas de Ligação a DNA/genética , Genes Ligados ao Cromossomo X , Spliceossomos/metabolismo , Síndromes de Tricotiodistrofia/genética , Células A549 , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Processamento Alternativo/genética , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Sobrevivência Celular/genética , Cisplatino/farmacologia , Citoproteção/efeitos dos fármacos , Dano ao DNA/genética , Proteína Quinase Ativada por DNA/metabolismo , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Íntrons/genética , Camundongos Endogâmicos NOD , Camundongos SCID , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Proteínas de Neoplasias/metabolismo , Fosforilação/efeitos dos fármacos , Estabilidade Proteica/efeitos dos fármacos , Subunidades Proteicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo
15.
Blood ; 135(9): 610-619, 2020 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-31942628

RESUMO

Traditionally, primary immune deficiencies have been defined based on increased susceptibility to recurrent and/or severe infections. However, immune dysregulation, manifesting with autoimmunity or hyperinflammatory disease, has emerged as a common feature. This is especially true in patients affected by combined immune deficiency (CID), a group of disorders caused by genetic defects that impair, but do not completely abolish, T-cell function. Hypomorphic mutations in the recombination activating genes RAG1 and RAG2 represent the prototype of the broad spectrum of clinical and immunological phenotypes associated with CID. The study of patients with RAG deficiency and with other forms of CID has revealed distinct abnormalities in central and peripheral T- and B-cell tolerance as the key mechanisms involved in immune dysregulation. Understanding the pathophysiology of autoimmunity and hyperinflammation in these disorders may also permit more targeted therapeutic interventions.


Assuntos
Imunodeficiência Combinada Severa/imunologia , Autoimunidade/genética , Autoimunidade/imunologia , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/imunologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/imunologia , Humanos , Proteínas Nucleares/deficiência , Proteínas Nucleares/imunologia , Imunodeficiência Combinada Severa/genética
16.
J Biol Chem ; 295(8): 2398-2406, 2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-31915249

RESUMO

Repair of DNA double-strand breaks by the nonhomologous end joining pathway is central for proper development of the adaptive immune system. This repair pathway involves eight factors, including XRCC4-like factor (XLF)/Cernunnos and the paralog of XRCC4 and XLF, PAXX nonhomologous end joining factor (PAXX). Xlf-/- and Paxx-/- mice are viable and exhibit only a mild immunophenotype. However, mice lacking both PAXX and XLF are embryonic lethal because postmitotic neurons undergo massive apoptosis in embryos. To decipher the roles of PAXX and XLF in both variable, diversity, and joining recombination and immunoglobulin class switch recombination, here, using Cre/lox-specific deletion to prevent double-KO embryonic lethality, we developed two mouse models of a conditional Xlf KO in a Paxx-/- background. Cre expressed under control of the iVav or CD21 promoter enabled Xlf deletion in early hematopoietic progenitors and splenic mature B cells, respectively. We demonstrate the XLF and PAXX interplay during variable, diversity, and joining recombination in vivo but not during class switch recombination, for which PAXX appeared to be fully dispensable. Xlf/Paxx double KO in hematopoietic progenitors resulted in a shorter lifespan associated with onset of thymic lymphomas, revealing a genome caretaking function of XLF/PAXX.


Assuntos
Reparo do DNA , Proteínas de Ligação a DNA/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Linfócitos/metabolismo , Animais , Medula Óssea/metabolismo , Proteínas de Ligação a DNA/deficiência , Switching de Imunoglobulina , Camundongos Endogâmicos C57BL , Camundongos Knockout , Análise de Sobrevida , Recombinação V(D)J/genética
17.
Cancer Lett ; 473: 148-155, 2020 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-31911080

RESUMO

The AT-rich interaction domain 1A (ARID1A, also known as BAF250a) is a chromatin remodeling gene, which frequently mutates across a broad spectrum of cancers with loss expression of the ARID1A protein. Recently, the association between ARID1A deficiency and immune checkpoint blockade (ICB) therapy has been reported. ARID1A deficiency contributes to the high microsatellite instability phenotype, increases tumor mutation burden, elevates expression of programmed cell death ligand 1 (PD-L1), and modulates the immune microenvironment, supporting the view that ARID1A loss might serve as a predictive biomarker for ICB. Furthermore, the therapeutic targeting strategies, which show "synthetic lethality" with ARID1A deficiency, exhibit potential synergy with ICB. We collectively reviewed the mechanisms underlying the correlation between ARID1A deficiency and ICB, the predictive function of ARID1A deficiency for ICB, and potential combined strategies of targeting agents, vulnerable for ARID1A deficiency, with ICB in cancer treatment.


Assuntos
Antineoplásicos Imunológicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Biomarcadores Tumorais/deficiência , Proteínas de Ligação a DNA/deficiência , Neoplasias/tratamento farmacológico , Fatores de Transcrição/deficiência , Animais , Antineoplásicos Imunológicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Biomarcadores Tumorais/genética , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/genética , Resistencia a Medicamentos Antineoplásicos/imunologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/imunologia , Humanos , Camundongos , Instabilidade de Microssatélites , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/patologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Mutações Sintéticas Letais/efeitos dos fármacos , Fatores de Transcrição/genética , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia
18.
Nature ; 577(7791): 566-571, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31915377

RESUMO

Epithelial-to-mesenchymal transitions (EMTs) are phenotypic plasticity processes that confer migratory and invasive properties to epithelial cells during development, wound-healing, fibrosis and cancer1-4. EMTs are driven by SNAIL, ZEB and TWIST transcription factors5,6 together with microRNAs that balance this regulatory network7,8. Transforming growth factor ß (TGF-ß) is a potent inducer of developmental and fibrogenic EMTs4,9,10. Aberrant TGF-ß signalling and EMT are implicated in the pathogenesis of renal fibrosis, alcoholic liver disease, non-alcoholic steatohepatitis, pulmonary fibrosis and cancer4,11. TGF-ß depends on RAS and mitogen-activated protein kinase (MAPK) pathway inputs for the induction of EMTs12-19. Here we show how these signals coordinately trigger EMTs and integrate them with broader pathophysiological processes. We identify RAS-responsive element binding protein 1 (RREB1), a RAS transcriptional effector20,21, as a key partner of TGF-ß-activated SMAD transcription factors in EMT. MAPK-activated RREB1 recruits TGF-ß-activated SMAD factors to SNAIL. Context-dependent chromatin accessibility dictates the ability of RREB1 and SMAD to activate additional genes that determine the nature of the resulting EMT. In carcinoma cells, TGF-ß-SMAD and RREB1 directly drive expression of SNAIL and fibrogenic factors stimulating myofibroblasts, promoting intratumoral fibrosis and supporting tumour growth. In mouse epiblast progenitors, Nodal-SMAD and RREB1 combine to induce expression of SNAIL and mesendoderm-differentiation genes that drive gastrulation. Thus, RREB1 provides a molecular link between RAS and TGF-ß pathways for coordinated induction of developmental and fibrogenic EMTs. These insights increase our understanding of the regulation of epithelial plasticity and its pathophysiological consequences in development, fibrosis and cancer.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Transição Epitelial-Mesenquimal , Fibrose/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Fatores de Transcrição/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Proteínas ras/metabolismo , Animais , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Feminino , Fibrose/patologia , Gastrulação , Humanos , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neoplasias/enzimologia , Organoides/metabolismo , Organoides/patologia , Proteínas Smad/metabolismo , Fatores de Transcrição da Família Snail/metabolismo , Fatores de Transcrição/deficiência , Fatores de Transcrição/genética , Fator de Crescimento Transformador beta/farmacologia
19.
Brain Dev ; 42(3): 289-292, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31955925

RESUMO

Atypical phenotype of an imprinting disease can develop with a recessive homozygous variant due to uniparental isodisomy. We present a girl with severe intellectual disability, developmental delay, distinctive facial features, and other neuropsychiatric features. Trio whole exome sequencing revealed a novel homozygous frameshift variant in AP4E1 [NM_007347.5:c.2412dupT:p.(Gly805Trpfs*8)] and uniparental isodisomy of chromosome 15 [iUPD(15)]. Single nucleotide polymorphism mapping analysis of exome data showed that the homozygous AP4E1 variant was derived from her heterozygous carrier father and unmasked by paternal iUPD(15). Brain magnetic resonance imaging confirmed the brain abnormalities characteristic of AP4 deficiency including the dilated ventricles and hypointensity in the globus pallidus in susceptibility-weighted imaging. This is the first case report of a combination of AP4E1 deficiency and Angelman syndrome. Our patient indicates that whole exome sequencing could uncover an atypical phenotype caused by multiple genetic factors including the uniparental isodisomy.


Assuntos
Síndrome de Angelman , Cromossomos Humanos Par 15/genética , Proteínas de Ligação a DNA/deficiência , Deficiências do Desenvolvimento , Transtornos Heredodegenerativos do Sistema Nervoso , Deficiência Intelectual , Dissomia Uniparental/genética , Síndrome de Angelman/genética , Síndrome de Angelman/patologia , Síndrome de Angelman/fisiopatologia , Pré-Escolar , Deficiências do Desenvolvimento/genética , Deficiências do Desenvolvimento/patologia , Deficiências do Desenvolvimento/fisiopatologia , Pai , Feminino , Transtornos Heredodegenerativos do Sistema Nervoso/genética , Transtornos Heredodegenerativos do Sistema Nervoso/patologia , Transtornos Heredodegenerativos do Sistema Nervoso/fisiopatologia , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Deficiência Intelectual/fisiopatologia , Fenótipo , Proteínas de Ligação a RNA
20.
Gynecol Oncol ; 156(3): 669-675, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31924330

RESUMO

OBJECTIVE: Mismatch repair (MMR) deficiency and Bethesda panel microsatellite instability (MSI) are increasingly analyzed to identify tumors that might benefit from immune checkpoint inhibitors, but tumor heterogeneity is a potential obstacle for such analyses. In ovarian cancer, data on intratumoral heterogeneity of MMR deficiency/MSI are lacking. METHODS: N = 582 ovarian cancers were screened for MMR deficiency by immunohistochemistry (IHC) on a tissue microarray. 10 cases suspect for MMR deficiency were identified among 478 interpretable cancers and repeated IHC on large sections combined with polymerase chain reaction (PCR)-based MSI analysis validated MMR deficiency/MSI in 9 of these tumors. RESULTS: MMR deficiency/MSI was predominantly seen in endmetrioid cancers (8 of 35, 23%) and also in 1 of 358 serous carcinomas (0.3%), but was absent in 34 mucinous carcinomas, 23 clear cell carcinomas, 17 malignant mixed Mullerian tumors (carcinosarcomas), and 11 mixed carcinomas. MMR deficiency involed protein loss of PMS2/MLH1 in 6 cases and of MSH2 and/or MSH6 in 3 cases. 7 MMR deficient cancers were MSI-high (all endometrioid), one was MSI-low (endometrioid) and one cancer with unequivocal MMR protein loss exhibited microsatellite stability (serous). MLH1 promotor methylation was observed in 4 of 5 endometrioid cancers with MLH1 protein loss. Immunostaining of all available cancer-containing tissue blocks (n = 114) of tumors with confirmed MMR deficiency/MSI revealed uniform MMR status throughout the entire tumor mass. CONCLUSIONS: Our data show that MSI is present in a substantial proportion of endometrioid ovarian cancers but can also occur in other tumor subtypes. MMR deficiency/MSI typically involves the entire tumor mass, suggesting that MMR inactivation occurs early in tumorigenesis in a subset of ovarian cancers.


Assuntos
Reparo de Erro de Pareamento de DNA , Enzimas Reparadoras do DNA/deficiência , Neoplasias Ovarianas/enzimologia , Neoplasias Ovarianas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Endometrioide/genética , Enzimas Reparadoras do DNA/genética , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Imuno-Histoquímica , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Endonuclease PMS2 de Reparo de Erro de Pareamento/deficiência , Endonuclease PMS2 de Reparo de Erro de Pareamento/genética , Proteína 1 Homóloga a MutL/deficiência , Proteína 1 Homóloga a MutL/genética , Proteína 2 Homóloga a MutS/deficiência , Proteína 2 Homóloga a MutS/genética , Análise Serial de Tecidos , Adulto Jovem
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